Question

Algebra 2 help please? I give medals!

Divide 5a^2 + 6a - 9 into 25a^4 + 19a^2 - a - 78.

Answer 1

I need to use long division by the way.

Answer 2

the key to long division is to focus on the first term of the dividend. 25a^4 here what will you multiply the divisor 5a^2+6a-9 by to get 25 a^4

Answer 3

5a^2?

Answer 4

correct. so multiply the divisor by 5a^2 and subtract from the dividend.

Answer 5

you'll see that the first term has been cancelled out

Answer 6

Okay so I multiply 5a^2 by 5a^2? and then it gives me 25a^4 which cancels it out?

Answer 7

correct, bu you also have to multiply the other terms of the divisor. after cancelling the first term re-adjust the remaining terms left from the divisor.

Answer 8

5a^2 (5a^2 + 6a - 9) = 25a^4 +30a^3-45a^2

Answer 9

only the first term cancels out the other terms have to be adjusted;30a^3-45a^2

Answer 10

Okay, still following.

Answer 11

re-adjust the terms keeping the one with the highest power of x in the front. follow the same steps to cancel out the first term and re-adjust the other terms. repeat these steps until you are left with a constant term or zero.

Answer 12

Okay so divide 19a^2 - a - 78 by 30 a^3?

Answer 13

you are left with 19a^2 - a - 78 from the dividend and 30a^3-45a^2 from the divisor. re-adjusting the two you get 30a^3-36a^2-a-78. now work to cancel the first term 30a^3

Answer 14

So don't you need to subtract 30a^3?

Answer 15

you have to, sorry wrote it wrong here, since it has been subtracted it would become
-30a^3 +64a^2-a-78

Answer 16

Okay so then you add it? @akitav

Answer 17

Can you help me @surjithayer ? he left.